[PATCH v4 1/2] power: regulator: add driver for ANATOP regulator

[Sean Anderson <sean.anderson@seco.com>]

On 3/26/21 7:44 AM, Ying-Chun Liu wrote:
> From: "Ying-Chun Liu (PaulLiu)" <paul.liu@linaro.org>
> 
> Anatop is an integrated regulator inside i.MX6 SoC.
> There are 3 digital regulators which controls PU, CORE (ARM), and SOC.
> And 3 analog regulators which controls 1P1, 2P5, 3P0 (USB).
> This patch adds the Anatop regulator driver.
> 
> Signed-off-by: Ying-Chun Liu (PaulLiu) <paul.liu@linaro.org>
> Cc: Fabio Estevam <fabio.estevam@nxp.com>
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Peng Fan <peng.fan@nxp.com>
> Cc: Sean Anderson <sean.anderson@seco.com>
> ---
> v2: add functions for set selector and delay. Define ANATOP_REGULATOR_STEP
> v3: add vin-supply. move regmap retrival to probe
> v4: check control_reg and return -ENOSYS if error. check vin-supply error
> ---
>   drivers/power/regulator/Kconfig            |  10 +
>   drivers/power/regulator/Makefile           |   1 +
>   drivers/power/regulator/anatop_regulator.c | 278 +++++++++++++++++++++
>   3 files changed, 289 insertions(+)
>   create mode 100644 drivers/power/regulator/anatop_regulator.c
> 
> diff --git a/drivers/power/regulator/Kconfig b/drivers/power/regulator/Kconfig
> index fbbea18c7d..faab311191 100644
> --- a/drivers/power/regulator/Kconfig
> +++ b/drivers/power/regulator/Kconfig
> @@ -312,6 +312,16 @@ config DM_REGULATOR_STPMIC1
>   	by the PMIC device. This driver is controlled by a device tree node
>   	which includes voltage limits.
>   
> +config DM_REGULATOR_ANATOP
> +	bool "Enable driver for ANATOP regulators"
> +	depends on DM_REGULATOR
> +	select REGMAP
> +	select SYSCON
> +	help
> +	Enable support for the Freescale i.MX on-chip ANATOP LDO
> +	regulators. It is recommended that this option be enabled on
> +	i.MX6 platform.
> +
>   config SPL_DM_REGULATOR_STPMIC1
>   	bool "Enable driver for STPMIC1 regulators in SPL"
>   	depends on SPL_DM_REGULATOR && PMIC_STPMIC1
> diff --git a/drivers/power/regulator/Makefile b/drivers/power/regulator/Makefile
> index 9d58112dcb..e7198da911 100644
> --- a/drivers/power/regulator/Makefile
> +++ b/drivers/power/regulator/Makefile
> @@ -30,3 +30,4 @@ obj-$(CONFIG_DM_REGULATOR_TPS65910) += tps65910_regulator.o
>   obj-$(CONFIG_DM_REGULATOR_TPS62360) += tps62360_regulator.o
>   obj-$(CONFIG_$(SPL_)DM_REGULATOR_STPMIC1) += stpmic1.o
>   obj-$(CONFIG_DM_REGULATOR_TPS65941) += tps65941_regulator.o
> +obj-$(CONFIG_$(SPL_)DM_REGULATOR_ANATOP) += anatop_regulator.o
> diff --git a/drivers/power/regulator/anatop_regulator.c b/drivers/power/regulator/anatop_regulator.c
> new file mode 100644
> index 0000000000..0eeb020df5
> --- /dev/null
> +++ b/drivers/power/regulator/anatop_regulator.c
> @@ -0,0 +1,278 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
> + * Copyright (C) 2021 Linaro
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <log.h>
> +#include <regmap.h>
> +#include <syscon.h>
> +#include <dm/device-internal.h>
> +#include <dm/device_compat.h>
> +#include <linux/bitops.h>
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/ioport.h>
> +#include <power/pmic.h>
> +#include <power/regulator.h>
> +
> +#define LDO_RAMP_UP_UNIT_IN_CYCLES      64 /* 64 cycles per step */
> +#define LDO_RAMP_UP_FREQ_IN_MHZ         24 /* cycle based on 24M OSC */
> +
> +#define LDO_POWER_GATE			0x00
> +#define LDO_FET_FULL_ON			0x1f
> +
> +#define BIT_WIDTH_MAX			32
> +
> +#define ANATOP_REGULATOR_STEP		25000
> +#define MIN_DROPOUT_UV			125000
> +
> +struct anatop_regulator {
> +	const char *name;
> +	struct regmap *regmap;
> +	struct udevice *supply;
> +	u32 control_reg;
> +	u32 vol_bit_shift;
> +	u32 vol_bit_width;
> +	u32 min_bit_val;
> +	u32 min_voltage;
> +	u32 max_voltage;
> +	u32 delay_reg;
> +	u32 delay_bit_shift;
> +	u32 delay_bit_width;
> +};
> +
> +static u32 anatop_get_bits(struct udevice *dev, u32 addr, int bit_shift,
> +			   int bit_width)
> +{
> +	const struct anatop_regulator *anatop_reg = dev_get_plat(dev);
> +	int err;
> +	u32 val, mask;
> +
> +	if (bit_width == BIT_WIDTH_MAX)
> +		mask = ~0;
> +	else
> +		mask = (1 << bit_width) - 1;
> +
> +	err = regmap_read(anatop_reg->regmap, addr, &val);
> +	if (err) {
> +		dev_dbg(dev, "cannot read reg (%d)\n", err);
> +		return err;
> +	}
> +
> +	val = (val >> bit_shift) & mask;
> +
> +	return val;
> +}
> +
> +static int anatop_set_bits(struct udevice *dev, u32 addr, int bit_shift,
> +			   int bit_width, u32 data)
> +{
> +	const struct anatop_regulator *anatop_reg = dev_get_plat(dev);
> +	int err;
> +	u32 val, mask;
> +
> +	if (bit_width == 32)
> +		mask = ~0;
> +	else
> +		mask = (1 << bit_width) - 1;
> +
> +	err = regmap_read(anatop_reg->regmap, addr, &val);
> +	if (err) {
> +		dev_dbg(dev, "cannot read reg (%d)\n", err);
> +		return err;
> +	}
> +	val = val & ~(mask << bit_shift);
> +	err = regmap_write(anatop_reg->regmap,
> +			   addr, (data << bit_shift) | val);
> +	if (err) {
> +		dev_dbg(dev, "cannot wrie reg (%d)\n", err);

nit: write

> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int anatop_get_voltage(struct udevice *dev)
> +{
> +	const struct anatop_regulator *anatop_reg = dev_get_plat(dev);
> +	u32 sel;
> +	u32 val;
> +
> +	if (!anatop_reg->control_reg)
> +		return -ENOSYS;
> +
> +	val = anatop_get_bits(dev,
> +			      anatop_reg->control_reg,
> +			      anatop_reg->vol_bit_shift,
> +			      anatop_reg->vol_bit_width);
> +
> +	sel = val - anatop_reg->min_bit_val;
> +
> +	return sel * ANATOP_REGULATOR_STEP + anatop_reg->min_voltage;
> +}
> +
> +static int anatop_set_voltage(struct udevice *dev, int uV)
> +{
> +	const struct anatop_regulator *anatop_reg = dev_get_plat(dev);
> +	u32 val;
> +	u32 sel;
> +	int ret;
> +
> +	dev_dbg(dev, "uv %d, min %d, max %d\n", uV, anatop_reg->min_voltage,
> +		anatop_reg->max_voltage);
> +
> +	if (uV < anatop_reg->min_voltage)
> +		return -EINVAL;
> +
> +	if (!anatop_reg->control_reg)
> +		return -ENOSYS;
> +
> +	sel = DIV_ROUND_UP(uV - anatop_reg->min_voltage,
> +			   ANATOP_REGULATOR_STEP);
> +	if (sel * ANATOP_REGULATOR_STEP + anatop_reg->min_voltage >
> +	    anatop_reg->max_voltage)
> +		return -EINVAL;
> +	val = anatop_reg->min_bit_val + sel;
> +	dev_dbg(dev, "calculated val %d\n", val);
> +
> +	if (anatop_reg->supply) {
> +		ret = regulator_set_value(anatop_reg->supply,
> +					  uV + MIN_DROPOUT_UV);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = anatop_set_bits(dev,
> +			      anatop_reg->control_reg,
> +			      anatop_reg->vol_bit_shift,
> +			      anatop_reg->vol_bit_width,
> +			      val);
> +
> +	return ret;
> +}
> +
> +static const struct dm_regulator_ops anatop_regulator_ops = {
> +	.set_value = anatop_set_voltage,
> +	.get_value = anatop_get_voltage,
> +};
> +
> +static int anatop_regulator_probe(struct udevice *dev)
> +{
> +	struct anatop_regulator *anatop_reg;
> +	struct dm_regulator_uclass_plat *uc_pdata;
> +	struct udevice *syscon;
> +	int ret = 0;
> +	u32 val;
> +
> +	anatop_reg = dev_get_plat(dev);
> +	uc_pdata = dev_get_uclass_plat(dev);
> +
> +	anatop_reg->name = ofnode_read_string(dev_ofnode(dev),
> +					      "regulator-name");
> +	if (!anatop_reg->name)
> +		return log_msg_ret("regulator-name", -EINVAL);
> +
> +	ret = device_get_supply_regulator(dev, "vin-supply",
> +					  &anatop_reg->supply);
> +	if (ret != -ENODEV) {
> +		if (ret)
> +			return log_msg_ret("get vin-supply", ret);
> +
> +		ret = regulator_set_enable(anatop_reg->supply, true);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = dev_read_u32(dev,
> +			   "anatop-reg-offset",
> +			   &anatop_reg->control_reg);
> +	if (ret)
> +		return log_msg_ret("anatop-reg-offset", ret);
> +
> +	ret = dev_read_u32(dev,
> +			   "anatop-vol-bit-width",
> +			   &anatop_reg->vol_bit_width);
> +	if (ret)
> +		return log_msg_ret("anatop-vol-bit-width", ret);
> +
> +	ret = dev_read_u32(dev,
> +			   "anatop-vol-bit-shift",
> +			   &anatop_reg->vol_bit_shift);
> +	if (ret)
> +		return log_msg_ret("anatop-vol-bit-shift", ret);
> +
> +	ret = dev_read_u32(dev,
> +			   "anatop-min-bit-val",
> +			   &anatop_reg->min_bit_val);
> +	if (ret)
> +		return log_msg_ret("anatop-min-bit-val", ret);
> +
> +	ret = dev_read_u32(dev,
> +			   "anatop-min-voltage",
> +			   &anatop_reg->min_voltage);
> +	if (ret)
> +		return log_msg_ret("anatop-min-voltage", ret);
> +
> +	ret = dev_read_u32(dev,
> +			   "anatop-max-voltage",
> +			   &anatop_reg->max_voltage);
> +	if (ret)
> +		return log_msg_ret("anatop-max-voltage", ret);
> +
> +	/* read LDO ramp up setting, only for core reg */
> +	dev_read_u32(dev, "anatop-delay-reg-offset",
> +		     &anatop_reg->delay_reg);
> +	dev_read_u32(dev, "anatop-delay-bit-width",
> +		     &anatop_reg->delay_bit_width);
> +	dev_read_u32(dev, "anatop-delay-bit-shift",
> +		     &anatop_reg->delay_bit_shift);
> +
> +	syscon = dev_get_parent(dev);
> +	if (!syscon) {
> +		dev_dbg(dev, "unable to find syscon device\n");
> +		return -ENOENT;
> +	}
> +
> +	anatop_reg->regmap = syscon_get_regmap(syscon);
> +	if (IS_ERR(anatop_reg->regmap)) {
> +		dev_dbg(dev, "unable to find regmap (%ld)\n",
> +			PTR_ERR(anatop_reg->regmap));
> +		return -ENOENT;
> +	}
> +
> +	/* check whether need to care about LDO ramp up speed */
> +	if (anatop_reg->delay_bit_width) {
> +		/*
> +		 * the delay for LDO ramp up time is
> +		 * based on the register setting, we need
> +		 * to calculate how many steps LDO need to
> +		 * ramp up, and how much delay needed. (us)
> +		 */
> +		val = anatop_get_bits(dev,
> +				      anatop_reg->delay_reg,
> +				      anatop_reg->delay_bit_shift,
> +				      anatop_reg->delay_bit_width);
> +		uc_pdata->ramp_delay = (LDO_RAMP_UP_UNIT_IN_CYCLES << val)
> +			/ LDO_RAMP_UP_FREQ_IN_MHZ + 1;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct udevice_id of_anatop_regulator_match_tbl[] = {
> +	{ .compatible = "fsl,anatop-regulator", },
> +	{ /* end */ }
> +};
> +
> +U_BOOT_DRIVER(anatop_regulator) = {
> +	.name = "anatop_regulator",
> +	.id = UCLASS_REGULATOR,
> +	.ops = &anatop_regulator_ops,
> +	.of_match = of_anatop_regulator_match_tbl,
> +	.plat_auto = sizeof(struct anatop_regulator),
> +	.probe = anatop_regulator_probe,
> +};
> 

With the above change:
Reviewed-by: Sean Anderson <sean.anderson@seco.com>